Our major concern with age gap relationships is the evolution of our species and the welfare of potential offspring
We think older middle aged men should respect the young girl, her family and future life for a girl under 25 who doesn’t have babies yet, who wants babys, and leave her alone out of respect for human life and each others dignity, unless they are choosing not to create a new life.
Science tells us an age gap means a woman and man live longer. Unless it’s the other way around and the woman is a "cougar" and the man is her toy boy, science fact.
I don’t see why any one would be jealous, it’s just not a good argument to put, and it can not be backed up with any proof either way so it’s just a feeling. People all over the “western world” see it as just vulgar, 10 years is ok but the further we get toward an age gap of 20 years, especially when the girl is under 25 It starts to look odd. We also think it’s a shame for the girl as it’s a sign of her previous circumstances i.e. poverty
There has been scientific research and there are statistics to show men’s sperm decreases in potency and health approaching the age of 40 that means there are an increase in mutations of the genetic code, but I can not post links just Google “the health of male sperm age 40”
The results if a baby is conceived: Higher risk of downs syndrome, schizophrenia and other birth defect, and a lower life expectancy. More problems with the baby means more complications at birth and the mother has a higher risk of fatality during pregnancy
To conclude, keeping things in balance and harmony is nature’s way and we can not escape the fact we are part of nature.